Here is another opinion on Carx and using kalk slurry to replace it. Luca Martino (Mahina Corals) on Reefbum podcast
He started this thread on R2R:
https://www.reef2reef.com/threads/say-you-could-slowly-dose-dry-calcium-hydroxide-kalk-in-a-reef-tank-water-mixing-chamber.808074/
I don't dose kalk on my current tank but you can calculate with "Kalk contribution calculator" - https://www.hamzasreef.com/Contents/Calculators/KalkContribution.php
Max amount of kalk you can dose is equivalent to your tank's evaporation rate.
Let do an example with the calculator above: tank...
Take a look at this build for a few ideas and references - it’s Hydros all the way except Maven
https://www.bareefers.org/forum/threads/nabils-81g-fiji-cube.35381/#post-503078
Tank looks great. Wow, the CC21 colony is amazing!
Quoting from reading/listening/watching @Thales, Dong, ..., ammonia "juice is not worth to squeeze". There is no real scientific study, evidence, stats to back it up. Nitrate is safer bet.
Besides copper, tin level is alarming - from searching google/internet:
Potential Harm to Shrimp: While some sources primarily focus on the effects of tin on corals, it's reasonable to infer that high tin levels could also negatively impact reef shrimp given their sensitivity to heavy metals...